Progressive arc quencher



Sept. 18, 1951 Q ns 2,568,470

PROGRESSIVE ARC QUENCHER Filed Dec. 29, 1949 2 Sheets-Sheet 1 1 vInventor:

Charles liTibus,

by W

His Attorney.

Sept. 18, 1951 c n'us 2,568,470

PROGRESSIVE ARC QUENCHER Filed Dec. 29, 1949 2 Sheets-Sheet 2 V 7%- M::/A// V 59" A Fig.4.

Inventor: Charfles f-LTious, b His Attorney.

Patented Sept. 18, 1951 Charles H. Tit-us, Philadelphia, Pa, assignor toGeneral Electric Company, a corporation of New York AppIicationDecember29, 1949,SerialN 0.1351596 1 claim. (Cl. 200''144) The invention relatesto are 'quen'chers, particularly arc quenchers for operation inconnection with the arcing contacts 'of 'heavy duty-circuitinterrupters.

The principal object is to provide an improved progressive type ofheavy-duty arc quencher having relatively movable slotted and 'landedarc-quenching membersone of which is-operable with acircuit-interrupting arcing contact for drawing the arc progressivelythrough restricted and enlarged spaces between the members so that theionized gases "sustaining the are are progressively brought intointimate contact "with the lands of the arc-quenching members in therestricted spaces and expanded in the enlarged slotted spaces andthereby rapidly become reduced in temperature and thus de-ionized toextinguish the are.

A further object is toenable a movable arcing contact mechanically tocarry the are along a narrow extended path between closely adjacentarc-quenching members of insulating material that are relatively movableand provided with opposing series of progressively registering slots andlands for, in effect, grinding and quenching the arc therebetween toinduce turbulence and pressure drop in the arc-sustaining gases andthereby expedite the arc-quenching action.

Another object is to provide an improved rotary type of arc quencherstructure having a rotatable arcing contact and progressivelyregistering concentric series f relatively rotatable slots and lands forrolling and quenching the arc gases therebetween within a relativelysmall quadrantal space.

Further objects and advantages of the invention will appear in theiollowing description of the accompanying drawings wherein Fig. 1 .is aside view of a heavy-duty circuitinterrupter provided with a rotatablymounted arcing "contact combined with-an improvedrot'ary arc quencherembodying the improvements of the present invention with the circuitinterrupter shown in the closed position; Fig.2 is a similar viewshowing the relative position of the parts when the circuit interrupteris opened and the are quenched; Fig. 3 is a partial sectional 'v-iewalong the-dash line 33 of Fig. -1 showing the details of construction of:the relatively ro'tatable arcquenching members; Fig. 4 is a side viewof a modified form of circuit interrupter provided with an arcingcontact movable in 'alinear path and combined with an arc quencherhaving pro- 'gressively registering linear series of slots and lands forquenching the arc therebetween 'in g accordance with the presentinvention.

As shown in 'Fig. 1, the "heavy-duty circuit finterrupter indicatedgenerally by the reference character 'la is of the improved rotaryarcing contact take-up type more fully described -and {60 claimed in thecopending application, Serial No. 135,796, filed December "29, 1949, byJohn A. Favre, and assigned to the 'assignee of the present invention.The circuit interrupter I0 is provided with a pair of maincurrent-carrying contacts H and [2 that are connected respectively tothe terminals [3 and I4 and also respectively to a pair of spaced-apartstationary arcing contacts Iii-that are aligned one behind the other asshown in Fig. 1. "One of the spaced-apart stationary arcing"con't'actslii is connected through conductors l6 and l'! with theterminal 13 while the other contact [5 is connected throughcondoctors?!) and 2| with the terminal 14.

As more fully described and claimed in the Fav're application, therotatably mounted bridging contact '22 for engaging and disengaging thepair of 'spaced apart stationary arcing contacts 15 is carried on acontact wear take-up arm 23 that is 'pivotally mounted 'on pin 24 which'in turn is carried on the rotatable "base plate 25. The base plate 25'is pivotally mounted on the stationary pin 26 by means of the yoke 27.

improved sequential "contact-operating mechanism, :also more fully"described and claimed in the Favre application, and indicated generallyby the reference character 39 is provided with a main operatingpush-pull rod 31 that is guided in a linear path between the concaverollers 32 and 33 'andhas a link 34 pivoted on ,pin 35 carrying roller35 and guided by the roller mounting pin 31 engaging with the slot"38formed in the stationary guide member 39 for movingroller 36 intoengagement 'with movable main contact 12 to force-contact l2 intowipingcircuit-closing engagement with the cooperating main contact 'I lagainst the strain of their re spective biasing springs 43 and 44. Thehooked member 45 is secured to contact l2 for engagement by pin '3"! toenforce the opening of the main contact 1 2 when rod 3! is moved in theopposite "direction.

The-main operating rod 31 also carries a link 46 pivoted 'at-one end onpin 4"! with the other end connected to the knee of the togg'le link-s48 and 4 9 that are pivoted respectively-on the stationary pin 50 andthe pin 5| carried by the pivotally mounted arm 23 so as to sequentiallyrotate the bridging contact 2 2 out of engagement with the pair ofspaced-apart stationary arcing contacts l5 after thesep'aration of themain contacts H and 12 :is completed. The disengagement-of the rotatablebridging-contact z-iefiects the .final interruption of the circuit .anddraws larcs between the bridging contact 2-2 and the spaced-apartstationary arcing -.c0ntacts l5. 7

V In accordance with the present invention, the arcs :are quicklyextinguished by the improved rotary type of progressive arcquencher-shown in "Figs. -1 iand 2 having relatively rotatable-completnntary' nested arid concentric cylindrical arcquenching members55 and 56 formed of suitable insulating materials such as moldedphosphoe asbestos to provide the several series of slots 51, 58, 59 and60 and a corresponding series of lands 6|, 62, 63 and 64 for quenchingthe arcs therel5 with the circuit breaker H) in its closed'posi tion.The series of slots 58 and lands 62 likewise are located in opposingconcentric alignment on the other side of the bridging contact 22 andthe arcing contacts I5 so as to effect progressive registration of thelands in each series with the slots and lands of the opposite seriesupon opening of the circuit breaker in order to quench the arctherebetween.

The stationary arc-quenching member 55 may be formed of an assemblage ofa concave arcuate insulating block provided with the series of slots 51and lands 61, and a concave arcuate insulating block H provided with theseries of slots 58 and the lands 62. The blocks 10 and II have suitableslots or openings for embedding the spaced-apart arcing contacts l5therebetween with the face of the arcing contracts in substantialalignment with the convex concentric cylindrical series of lands 6! and62 of the blocks as indicated in Fig. 3. The blocks 70 and H arerespectively further provided with deep central arcuate grooves 12 and13 extending in alignment midway between the spaced-apart arcingcontacts 15 as shown more clearly in the partial sectional view of Fig.3.

The rotatably mounted complementary nesting convex arcing member 56 isof substantially semicylindrical form with suitable provision made forembedding the bridging contact 22 within a recess or tunnel '15 formedtherein for receiving the U-shaped bridging member 22 therein whilepermitting free substantially radial movement of the bridging contact 22when the arm 23 on which the bridging member 22 is mounted is rotatedabout the pin 24. The rotating arc-quenching member 55 is suitablysecured to the mounting plate 25 so as to rotate about the pin 26 as anaxis and thereby maintain relatively close running clearance between theseries of lands 63 and 64 formed thereon and the opposing concentriccylindrical series of lands 61 and 62. The rotatably mountedarc-quenching member 56 is provided with a central arcuateshaped vane 14that extends into a freelyrunning fit with the arcuate concentricallyaligned grooves 12 and 13 so as to provide a continuously effectiveinsulating barrier between the two spaced-apart arcing contacts 15during the relative rotary motion of the movable arcingmember 55 withrespect to the stationary arcing member 55 formed by the two concaveblocks 16 and IL Operation Referring to Fig. 1, when the operatingrod'3l is lowered by suitable automatic overload current-responsivemeans, not shown, the main contacts II and 12 are separated by operationof the link 34 and'roller 31 with the hooked member serving to apply apositive force in addition to the opening bias of springs 43 to effectthe separation. The separation of the main contacts I l and I2 shuntsthe-current through the spaced-apart 4 arcing contacts 15 and thebridging contact 22 Upon the rapid sequential separation of the bridgingcontact 22 from the spaced-apart arcing contacts I5 by operation of link46 to buckle the toggle links 48 and 49, arm 23 is rotated about pin 24to withdraw the bridging contact 22 sub stantially radially within therecess or tunnel 15.

At the same time the mounting plate 25 is rotated about pin 26 to carrythe semicylindrical arcing member 56 along with the bridging contact 22so as to mechanically draw the arcs formed between the bridging contact22 and the stationary arcing contacts [5 along a narrow path extendingbetween the closely adjacent nesting cylindrical arc-quenching members55 and 56. In this way, the opposing series of lands 63 and 64 on ,themovable arc-quenching member 56 are progressively brought into registerwith the slots 5'! and 58 and lands 6| and 62 to quench the arcstherebetween upon rotary movement of the pivotally mounted arc-quenchingmember 56 and bridging contact 22. As a result, the ionized gasessustaining the arcs are brought into intimate contact with the lands ofthe relatively movable arc-quenching members when the lands register andexpand in the slots between the lands when the slots register so as toinduce turbulence and pressure drop in the arc-sustaining gases andthereby expedite the arc-quenching action to extinguish the arc beforethe parts reach their relative position shown in Fig. 2.

During the quenching of the arc between the progressively registeringlands and slots of the relatively movable arc-quenching members 55 and56, the arcuate barrier 14 that runs in the aligned arcuate slots 1'2and 13 serves to effectively separate the arcs drawn at the oppositeends of the U-shaped bridging member 22 so that the hot gases sustainingeach are are forced into intimate turbulent engagement with therelatively movable slots and lands on either side of the control barrier14 to become rapidly cooled, thereby increase the arc resistance at eachrestricted section and extinguish each arc in a relatively smallquadrantal space. The slots between the lands provide for venting thearc gases laterally therethrough and suitable barrier plates, not shown,may be spaced apart on each side of the relatively movable arc-quenchingmembers 55 and 56 in the path of the vented gases. The rapidly expandinggases are cooled and rapidly deionized in order to increase thedielectric strength of the gas. The increased dielectric strengthpermits a higher steady state and transient recovery voltage to beinterrupted.

In the modified form of circuit interrupter, shown in Fig. 4, thepush-pull operating rod carries a bridging contact 8| in a linear pathfor engaging between the relatively stationary contacts 82 and 83.However, the contact 82 is pivotally mounted upon the terminal 84 bymeans of the conducting pin 35 and is biased into engagement with thebridging contact 8! by spring 86. Likewise, contact 83 is pivotallymounted on the terminal 8'l'by means of the conducting pin 85 and isbiased to engage the bridging contact 8| by the spring 89.

In order to quench the arcs drawn upon separation of the bridgingcontact 8| from the pair of relatively stationary contacts 62 and 83 inaccordance with the present invention, two rows of insulating plates 94and 95, formed of suitablevarc resistant insulating material, are

mounted between the front and back plates 56 and 91, also formed ofinsulating material, in parallel spaced alignment adjacent the linearpath of the bridging contact BI and in predetermined linear alignmentwith the respective contacts 82 and 83 to provide alternate series oflands 98 and 99 and slots I and IN on opposite sides of the linear pathof bridging contact 8Iv The bridging contact 8| carries for movementtherewith an insulating member I04 having the series of slots I05 andI05a formed on the opposite sides thereof to provide a correspondingseries of lands I06 and I0! for progressively registering with theopposing alternate series of lands 98 and 99 and slots I00 and IOI toquench the arcs therebetween in substantially the same Way as theprogressively registering slots and lands of the rotary type of circuitinterrupter previously described. Thus, the ionized gases sustaining theare drawn between the bridging contact 8| and the cooperating contact 82prior to interruption of the circuit are progressively brought intointimate contact with the series of lands 98 and I08 causing the arcresistance to rise over the restricted sections upon the progressiveregistration thereof and are expanded in the enlarged spaces providedupon the progressive registration of the series of slots I00 and I05 andthereby rapidly become reduced in temperature and thus deionized toextinguish the arc. Exactly the same arc-quenching is provided by theprogressively registering series of lands 99 and I0! and progressivelyregistering series of slots IOI and I06 to quench the arc drawn betweenthe bridging contact BI and the cooperating contact 83. The alternateregistration of the lands and slots induces turbulence and pressure dropin the arcsustaining gases and thereby expedites the arcquenching actionby virtue of forcing the ar into a series of restricted, highresistance, $1101 a arcs having intervening sections which are rapidlydeionized by quickly cooled gases which are then capable of withstandinghigh recovery voltages of a transient and a steady state nature.

III

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

In combination, a concave arcuate arc-quenching member provided with aseries of alternate slots and lands transverse the concave arcuate facethereof and having an arcuate slot formed circumferentially therein, apair of axially spaced-apart arcing contacts embedded in the concavemember with the ends of the contacts in substantial alignment with thelands on opposite sides of the arcuate slot, a convex arcuatearc-quenching member rotatably mounted in nesting relation with theconcave member and provided with a series of alternate slots and landstransverse the convex face thereof and having a bridging contact movabletherewith for engagement with the spaced-apart arcing contacts, andmeans for rotating the convex member to disengage the bridging contactand draw arcs between the bridging contact and spaced-apart arcingcontacts and progressively register the slots and lands of the rotatableconvex arcquenching member with the slots and lands of the concaveinsulating member to quench the arc therebetween, and having an arcuatebarrier extending centrally therefrom into the arcuate slot formed inthe concave member for separating the arcs.

CHARLES H. TI'IUS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,199,607 Bakken May 7, 19402,315,618 Hufistutter Apr. 6, 1943 2,416,185 Leeds Feb. 18, 19472,452,477 Leeds Oct. 26, 1948

